JPH10318621A - Freezing cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly adjust the amount of utilization of stored heat by providing an operation means for dividing the flow of a refrigerant through an indoor heat exchanger and returning it to a compressor through a heat-storing device and for performing heating operation while utilizing stored heat as well as absorbed heat from external air and then gradually increasing the travel of an electro motor operated expansion valve from the initial opening. SOLUTION: On heating operation for simultaneously utilizing absorbed heat and stored heat from external air, the discharge refrigerant from a compressor 1 is returned to a compressor 1 via an indoor heat exchanger 4, an electro motor operated expansion valve 6, an outdoor heat exchanger 7, and a suction cup 8. At the same time, the flow of a refrigerant through a two-way valve 5 is divided and is circulated so that it returns to the compressor 1 via a capillary tube 12, a heat exchanger 14 of a heat storage tank 13, and a suction cup 15. The heat storage tank 13 accommodates a heat storage agent and warm heat for heating is stored in the heat storage agent in advance, for example, by an electric heater that utilizing, for example, night-time power. In this case, when heating is started, the opening of the electro motor operated expansion valve 6 is gradually increased from the initial opening by controlling, thus properly adjusting the amount of utilization of stored heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a refrigeration cycle apparatus having a heat storage function.

[0002]

2. Description of the Related Art There is a refrigeration cycle apparatus in which a heat storage tank is provided in a refrigeration cycle, and heat for heating is stored by heat storage using, for example, nighttime electric power, and the stored heat is used for air conditioning.

[0003]

In the case of a refrigeration cycle apparatus having a heat storage function, it is desired that the amount of heat storage can be appropriately adjusted. As a method of adjustment, it is conceivable to provide a flow control valve in the refrigerant flow path to the heat storage tank, but there is a problem that the use of the flow control valve causes an increase in cost.

[0004] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a refrigeration cycle device capable of appropriately adjusting the amount of heat storage without increasing the cost.

[0005]

Means for Solving the Problems First Invention (Claim 1)
The refrigeration cycle device is a refrigeration cycle device having a compressor, an indoor heat exchanger, an electric expansion valve, an outdoor heat exchanger, and heat storage means, the refrigerant discharged from the compressor is an indoor heat exchanger,
Heating operation utilizing heat storage together with heat absorption from outside air, while returning to the compressor through the electric expansion valve and outdoor heat exchanger and returning the refrigerant passing through the indoor heat exchanger to the heat storage means and returning to the compressor. Operating means for performing the operation, and when the heating means starts heating, the opening of the electric expansion valve is gradually increased from the initial opening.

In a refrigeration cycle apparatus according to a second invention (claim 2), in the first invention, the control means gradually increases the opening of the electric expansion valve from the initial opening according to the time measured by the timer. In a refrigeration cycle apparatus according to a third invention (claim 3), in the first invention, the control means controls an opening degree of the electric expansion valve.
The degree of opening gradually increases from the initial opening according to the temperature change of the heat storage means or the temperature change of the refrigerant passing through the heat storage means.

[0007] A refrigeration cycle apparatus according to a fourth invention (claim 4) is a refrigeration cycle apparatus comprising a compressor, an indoor heat exchanger, a pressure reducing means, an outdoor heat exchanger, and a heat storage means. First operating means for passing the discharged refrigerant through the indoor heat exchanger, the decompression means, and the outdoor heat exchanger to the compressor and performing a heating operation utilizing heat absorption from the outside air; and discharging the refrigerant discharged from the compressor to the indoor heat exchanger. In addition to returning to the compressor through the decompression means and the outdoor heat exchanger, the refrigerant flowing through the indoor heat exchanger is diverted and returned to the compressor through the heat storage means, and the heating operation utilizing heat storage together with heat absorption from outside air is performed. A second operating means for performing the operation, wherein the initial opening degree of the electric expansion valve is made different between a case where the first operating means starts heating and a case where the second operating means starts heating.

In a refrigeration cycle apparatus according to a fifth aspect of the present invention, in the fourth aspect, the control means changes the initial opening of the electric expansion valve in accordance with the outside air temperature. In a refrigeration cycle apparatus according to a sixth invention (claim 6), in the fourth invention, the control means changes the initial opening degree of the electric expansion valve according to the temperature of the heat storage means during heating by the second operation means. .

In a refrigeration cycle apparatus according to a seventh invention (claim 7), in the fourth invention, the control means makes the initial opening degree of the electric expansion valve further differ according to the outside air temperature, and
The initial opening degree of the electric expansion valve during heating by the operating means is made different depending on the temperature of the heat storage means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, reference numeral 1 denotes a compressor, and two compression chambers (cylinders) 1 having different capacities.
a and 1b. 1a is larger and 1b is smaller.

An indoor heat exchanger 4 is connected to the discharge port of the compressor 1 via a four-way valve 2 and a two-way valve 3, and the indoor heat exchanger 4 has a two-way valve 5 and a pressure reducing means such as an electric expansion valve. An outdoor heat exchanger 7 is connected via a pipe 6. The electric expansion valve 6 is a pulse motor valve (PMV) whose opening changes according to the number of supplied drive pulses.

The outdoor heat exchanger 7 is connected to the compression chambers 1a and 1b of the compressor 1 via a four-way valve 2 and a suction cup 8, respectively. Compression chamber 1 from suction cup 8
A check valve 10 is provided in both pipes leading to a.

The above is the configuration of a general heat pump refrigeration cycle. The two-way valve 5 and the electric expansion valve 6
And a pipe connected to the compression chamber 1a, a heat storage utilizing two-way valve 11, a capillary tube 12 as a pressure reducing means, a heat exchanger 14 of a heat storage tank 13 as a heat storing means, and a suction cup 15 in order. Piping is connected.

On the other hand, the control unit 20 includes a compressor 1, a four-way valve 2, a two-way valve 3, a two-way valve 5, an electric expansion valve 6, a two-way valve 11,
The operation unit 21 and the timer 22 are connected. Control unit 2
0 has the following [1] to [3] as main functional means.

[1] Four-way valve 2, two-way valve 3, indoor heat exchanger 4, two-way valve 5, electric expansion valve 6, indoor heat exchanger 7, four-way valve 2, suction cup 8. First operating means for performing a normal heating operation using only heat absorbed from outside air by returning to the compressor 1 through the check valves 9 and 10.

[2] The refrigerant discharged from the compressor 1 is supplied to the four-way valve 2, the two-way valve 3, the indoor heat exchanger 4, the two-way valve 5, the electric expansion valve 6, the indoor heat exchanger 7, the four-way valve 2, and the suction cup. 8. Returning to the compressor 1 through the check valves 9 and 10, the refrigerant flowing through the two-way valve 5 is divided and the two-way valve 11 and the capillary tube 1 are divided.
2. Second operating means for returning to the compressor 1 through the heat exchanger 14 and the suction cup 15 of the heat storage tank 13 and performing a heating operation utilizing heat absorption from outside air and heat storage simultaneously.

[3] Control means for gradually increasing the opening of the electric expansion valve 6 from the initial opening when heating is started by the second operating means. Next, the operation of the above configuration will be described.

Heating is started by the second operating means in a heating operation in which heat absorption from outside air and heat storage are simultaneously used. That is, while the compressor 1 is started, the four-way valve 2 is switched to the state shown in FIG. 1, and the two-way valves 3 and 5 are opened. Further, the electric expansion valve 6 is set to a predetermined initial opening, and the two-way valve 11 is opened.

The refrigerant discharged from the compressor 1 flows through the four-way valve 2 and the two-way valve 3 to the indoor heat exchanger 4, and a part of the refrigerant passing through the indoor heat exchanger 4 is partially discharged to the two-way valve 5 and the electric expansion valve. 6 to the indoor heat exchanger 7. And the indoor heat exchanger 7
Is passed through the four-way valve 2, the suction cup 8, and the check valve 10, and is sucked into the compressor 1. Outdoor heat exchanger 7
The refrigerant flowing through the air draws heat from the outside air and evaporates.

Further, the remaining refrigerant that has passed through the indoor heat exchanger 4 is diverted to the two-way valve 11, passes through the two-way valve 11 and the capillary tube 12, and passes through the heat exchanger 1 of the heat storage tank 13.
Flow into 4.

The heat storage tank 13 is a heat storage agent (for example, water).
Is stored in the heat storage agent in advance by, for example, an electric heater (not shown) using nighttime electric power. The refrigerant flowing through the heat exchanger 14 loses this heat (heat) and evaporates.

The refrigerant having passed through the heat exchanger 14 passes through the four-way valve 2 and the suction cup 15 and is sucked into the compression chamber 1a of the compressor 1. The refrigerant flowing through the heat exchanger 14 removes heat from the heat storage agent and evaporates.

In this case, the refrigerant that has passed through the heat storage tank 13 only flows from the suction cup 15 into the compression chamber 1a but does not flow into the compression chamber 1b. Compared with the case where the refrigerant flows into both the compression chambers 1a and 1b, the flow rate of the refrigerant in the heat exchanger 14 is reduced, and the utilization rate of the heat storage is suppressed.

In this way, by simultaneously utilizing the heat absorption and the heat storage from the outside air, it is possible to perform heating with a rapid rise. By the way, the timer 22
Is working. The opening of the motor-operated expansion valve 6 is the initial opening P1 while the time of the timer 22 is less than T1, but the opening of the motor-operated expansion valve 6 is P2 during the period when the time of the timer 22 is not less than T1 and less than T2. (> P1). Timer 2
During the period in which the time 2 is equal to or more than T2 and less than T3, the opening of the electric expansion valve 6 is set to P3 (> P2). When the time measured by the timer 22 is equal to or longer than T3, the opening degree of the electric expansion valve 6 becomes P4 (> P
3) is set. Table 1 shows the relationship between the passage of time and the degree of opening of the electric expansion valve 6.

[0025]

[Table 1]

As the degree of opening of the electric expansion valve 6 increases, the amount of the refrigerant flowing from the indoor heat exchanger 4 to the outdoor heat exchanger 7 increases, and the refrigerant is accordingly diverted to the heat exchanger 14 of the heat storage tank 13. The amount of refrigerant is reduced.

That is, in a situation where a large amount of heating heat is required, such as at the start of heating, the heat storage is fully utilized without reducing the amount of the refrigerant flowing through the heat exchanger 14 of the heat storage tank 13, and then the heating is performed. As the required amount of heating heat decreases, the amount of refrigerant flowing through the heat exchanger 14 is gradually reduced to reduce the amount of heat storage used.

Therefore, the amount of heat storage can be appropriately adjusted. In particular, since the adjustment is performed using the electric expansion valve 6 which is an original component of the refrigeration cycle, it is not necessary to provide a new flow control valve in the refrigerant flow path to the heat storage tank 13, thereby avoiding an increase in cost. Can be.

Thereafter, when the elapsed time from the start of heating reaches a predetermined time based on the time measured by the timer 22, the first operating means determines that the rising of heating is almost completed, and the first operating means starts the operation from outside air. A normal heating operation using only heat absorption is performed. That is, four-way valve 2, two-way valve 3, 5,
While the electric expansion valve 6 and the two-way valve 16 remain in the same state, the two-way valve 1
1 is closed.

The refrigerant discharged from the compressor 1 flows through the four-way valve 2 and the two-way valve 3 to the indoor heat exchanger 4, and the refrigerant having passed through the indoor heat exchanger 4 passes through the two-way valve 5 and the electric expansion valve 6. And flows to the indoor heat exchanger 7. Then, the refrigerant that has passed through the indoor heat exchanger 7 passes through the four-way valve 2, the suction cup 8, and the check valves 9 and 10 and is sucked into the compressor 1. The refrigerant flowing through the outdoor heat exchanger 7 absorbs heat from outside air and evaporates. Table 2 shows the relationship between the operation mode and the operation of the electric expansion valve 6 and the two-way valve 11. The opening of the electric expansion valve 6 is a predetermined opening including the initial opening.

[0031]

[Table 2]

By the way, during the transition from heating using heat absorption and heat storage from outside air to heating using only heat absorption from outside air, the evaporation pressure of the refrigerant in the heat exchanger 14 of the heat storage tank 13 increases at a stroke. There is a concern that the pressure may change and appear as a sudden increase in the load on the compressor 1. However, when shifting from heating using heat storage to heating using only heat absorption from outside air, as described above, the opening of the electric expansion valve 6 increases and the heat storage tank 13
Since the amount of the refrigerant flowing through the heat exchanger 14 is set to be small, it is possible to avoid a sudden change in the evaporation pressure in the heat exchanger 14 and to avoid a sudden increase in the load applied to the compressor 1. be able to.

In the above embodiment, the opening of the electric expansion valve 6 is gradually increased from the initial opening according to the time measured by the timer 22, but the temperature of the heat storage tank 13 is used instead of the time measured by the timer 22. You may.

That is, as shown in FIG. 1, a heat storage temperature sensor 30 is provided in the heat storage tank 13 and connected to the control unit 20. The heat storage temperature sensor 30 detects the temperature Tw of the heat storage agent (for example, water) in the heat storage tank 13.

The controller 20 gradually increases the opening of the electric expansion valve 6 from the initial opening in accordance with a change in the temperature detected by the heat storage temperature sensor 30. For example, when the detected temperature Tw of the heat storage temperature sensor 30 is equal to or higher than Tw3, the opening of the electric expansion valve 6 is set to the initial opening P1, and the detected temperature Tw is lower than Tw3 and Tw2.
In the above case, the opening of the electric expansion valve 6 is set to P2 (> P1). When the detected temperature Tw is lower than Tw2 and higher than Tw1, the opening of the electric expansion valve 6 is set to P3 (> P2). When the detected temperature Tw is lower than Tw1, the opening of the electric expansion valve 6 is set to P4 (> P3). Thermal storage temperature sensor 3
Table 3 shows the relationship between the detected temperature Tw of 0 and the opening degree of the electric expansion valve 6.
Shown in

[0036]

[Table 3]

Also in this case, in a situation where a large amount of heating heat is required such as at the start of heating, the heat storage is fully utilized without reducing the amount of refrigerant flowing through the heat exchanger 14 of the heat storage tank 13. With the progress of heating and a decrease in the required heating heat amount, the amount of refrigerant flowing through the heat exchanger 14 is gradually reduced to reduce the amount of heat storage, and accordingly, the amount of heat storage can be appropriately adjusted. it can.

The heat storage temperature sensor 30 detects the heat storage tank 1
3, the temperature Tw of the heat storage agent in the heat storage tank 13 is detected.
The temperature of the refrigerant that has passed through may be detected, and the opening of the electric expansion valve 6 may be gradually increased in accordance with the change in the detected temperature.

Next, a second embodiment of the present invention will be described. As the function means of the control unit 20, the following [4] is employed instead of [3] of the first embodiment.

[4] The initial opening of the motor-operated expansion valve 6 is controlled by the heating operation using the heat absorption from the outside air and the heat storage at the same time, or by the normal heating operation using only the heat absorption from the outside air. Control means for making it different from when it starts. Other configurations are the same as those of the first embodiment. Table 4 shows the relationship between the operation mode and the operation of the electric expansion valve 6 and the two-way valve 11.

[0041]

[Table 4]

That is, from the viewpoint of appropriately adjusting the amount of heat storage, when heating is started by a heating operation in which heat absorption from outside air and heat storage are simultaneously used, Y is set as the initial opening of the electric expansion valve 6, When heating is started by a normal heating operation using only heat absorption from outside air, X is set as the initial opening degree. After a predetermined time from the start of heating, the degree of opening of the electric expansion valve 6 is appropriately controlled according to, for example, the degree of superheat of the refrigerant in the outdoor heat exchanger 7.

It should be noted that the initial opening of the electric expansion valve 6 is not limited to the operation mode at the start of heating, and may be made different depending on the outside air temperature. This also leads to appropriate adjustment of the amount of heat storage.

That is, as shown in FIG. 1, an outside air temperature sensor 23 is provided and connected to the control unit 20. The outside air temperature sensor 23 detects the outside air temperature To. Control unit 20
Sets the initial opening of the electric expansion valve 6 to the detection temperature To of the outside air temperature sensor 23 in accordance with the operation mode at the start of heating.
Depending on, make it different.

For example, in the case of starting heating in which heat absorption and heat storage from outside air are simultaneously used, when the detection temperature To of the outside air temperature sensor 23 is lower than To1, the initial opening of the electric expansion valve 6 is set to Y1, and the detection temperature To Is greater than or equal to To1 and less than To2, the initial opening is set to Y2 (> Y1). When the detected temperature To is equal to or higher than To2 and lower than To3, the initial opening is set to Y3 (> Y2). When the detected temperature To is equal to or higher than To3, the initial opening is set to Y4 (> Y3).

The lower the outside air temperature To is, the smaller the initial opening is, and the more the amount of heat stored is used. In the case of heating start using only heat absorption from the outside air, when the detection temperature To of the outside air temperature sensor 23 is lower than To1, the initial opening of the electric expansion valve 6 is set to X1, and the detection temperature To is equal to or higher than To1.
In the range below T02, the initial opening is set to X2 (> X1). When the detected temperature To is equal to or higher than To2 and lower than T03, the initial opening is set to X3 (> X2). When the detected temperature To is equal to or higher than To3, the initial opening is set to X4 (> X3).

The lower the outside air temperature To is, the smaller the initial opening is, so that the control opening can be promptly shifted to the control opening in the normal control. Table 5 shows the relationship between the operation mode, the outside air temperature To, and the initial opening.

[0048]

[Table 5]

Up to this point, the initial opening of the electric expansion valve 6 has been
The case where the heating mode is changed according to the operation mode at the start of heating and the outside air temperature To has been described. However, the configuration may be changed according to the operation mode at the time of heating start and the detection temperature Tw of the heat storage temperature sensor 30. It may be configured to differ depending on the operation mode at the time, the outside air temperature To, and the detected temperature Tw of the heat storage temperature sensor 30. In addition, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

[0050]

As described above, according to the present invention, when heating is started by heating operation utilizing heat storage together with heat absorption from the outside air, the opening of the electric expansion valve is gradually increased from the initial opening. Alternatively, the heating is started by the heating operation in which the initial opening of the electric expansion valve 6 is simultaneously used to absorb heat from the outside air and the heat storage, and by the normal heating operation in which only the heat absorption from the outside air is used. Since the configuration is different from that in the case, it is possible to provide a refrigeration cycle apparatus capable of appropriately adjusting the amount of heat storage without increasing the cost.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of each embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor 1a, 1b ... Compression chamber 2 ... Four-way valve 3, 5 ... Two-way valve 4 ... Indoor heat exchanger 6 ... Electric expansion valve 7 ... Outdoor heat exchanger 11 ... Heat storage utilization two-way valve 13 ... Heat storage tank 14 ... heat exchanger 20 ... control unit 22 ... timer 23 ... outside air temperature sensor 30 ... heat storage temperature sensor

Claims (7)

[Claims] 1. A refrigeration cycle apparatus comprising a compressor, an indoor heat exchanger, an electric expansion valve, an outdoor heat exchanger, and heat storage means, wherein refrigerant discharged from the compressor is supplied to the indoor heat exchanger, an electric expansion valve, Operating means for returning to the compressor through the outdoor heat exchanger, diverting the refrigerant passing through the indoor heat exchanger, returning to the compressor through the heat storage means, and performing a heating operation utilizing heat storage together with heat absorption from outside air. And a control means for gradually increasing the opening of the electric expansion valve from the initial opening when heating by the operating means is started. 2. The refrigeration cycle apparatus according to claim 1, wherein the control means gradually increases the opening of the electric expansion valve from the initial opening according to the time measured by a timer. 3. The control means controls the opening degree of the electric expansion valve.
2. The refrigeration cycle apparatus according to claim 1, wherein the degree of opening is gradually increased from an initial opening according to a temperature change of the heat storage means or a temperature change of the refrigerant passing through the heat storage means. 4. A refrigeration cycle apparatus comprising a compressor, an indoor heat exchanger, a pressure reducing means, an outdoor heat exchanger, and a heat storage means, wherein the refrigerant discharged from the compressor is supplied to the indoor heat exchanger, a pressure reducing means,
A first operating unit for returning to the compressor through the outdoor heat exchanger and performing a heating operation utilizing heat absorption from the outside air; and an indoor heat exchanger, a decompression unit for discharging refrigerant discharged from the compressor,
A second heating operation is performed in which the refrigerant passes through the outdoor heat exchanger and returns to the compressor, the refrigerant that has passed through the indoor heat exchanger is diverted, returns to the compressor through the heat storage means, and uses heat storage together with heat absorption from outside air. Operating means, and control means for making an initial opening degree of the electric expansion valve different between a case where heating is started by the first operating means and a case where heating is started by the second operating means. Refrigeration cycle device. 5. The refrigeration cycle apparatus according to claim 4, wherein the control means changes the initial opening of the electric expansion valve in accordance with the outside air temperature. 6. The refrigeration cycle apparatus according to claim 4, wherein the control unit changes the initial opening of the electric expansion valve according to the temperature of the heat storage unit when the second operation unit heats. 7. The control means makes the initial opening of the electric expansion valve different according to the outside air temperature, and changes the initial opening of the electric expansion valve during heating by the second operating means to the temperature of the heat storage means. The refrigeration cycle apparatus according to claim 4, wherein the refrigeration cycle apparatus is different depending on the refrigeration cycle apparatus.